IL6 and Parkinson disease: Tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6 and transforming growth factor (TGF) levels were elevated in the substantia nigra DA neurons and also in cerebrospinal fluid (CSF) in sporadic PD [3], and TNF-α and IL-6 were also present in microglia of PD brain [4].